Package org.eclipse.rdf4j.examples.function

Class ExistingPalindromeFunction

java.lang.Object
org.eclipse.rdf4j.examples.function.ExistingPalindromeFunction
All Implemented Interfaces:
Function
public class ExistingPalindromeFunction extends Object implements Function
An example custom SPARQL function that detects palindromes that already exist in the database.
Author:
Jeen Broekstra

  • Field Details

  • Constructor Details

    • ExistingPalindromeFunction

      public ExistingPalindromeFunction()

  • Method Details

    • getURI

      public String getURI()
      return the URI 'http://example.org/custom-function/existingPalindrome' as a String
      Specified by:
      getURI in interface Function

    • evaluate

      public Value evaluate(TripleSource tripleSource, Value... args) throws ValueExprEvaluationException
      Executes the existingPalindrome function.
      Specified by:
      evaluate in interface Function
      Parameters:
      tripleSource - the TripleSource used in the query evaluation. This can be used to access the current state of the store.
      args - the function input arguments.
      Returns:
      A boolean literal representing true if the input argument is a palindrome and exists in the database, false otherwise.
      Throws:
      ValueExprEvaluationException - if more than one argument is supplied or if the supplied argument is not a literal.

    • evaluate

      public Value evaluate(ValueFactory valueFactory, Value... args) throws ValueExprEvaluationException
      Description copied from interface: Function
      Evaluate the function over the supplied input arguments, using the supplied ValueFactory to produce the result.
      Specified by:
      evaluate in interface Function
      Parameters:
      valueFactory - a ValueFactory to use for producing the function result.
      args - the function input arguments.
      Returns:
      the function result value.
      Throws:
      ValueExprEvaluationException